We are about to see a beautiful demonstration of this with the British economy, where the official statisticians will shortly entirely and drastically rewrite decades of history...

One change will see research and development spending classified as capital expenditure; at a stroke, this will raise the level of the UK's economic output by a cool £25bn.

That’s just the beginning: overall, the statistical deckchair shuffling will boost the size of the UK economy by between 2.5 and five per cent, a shockingly large amount (and a vast range that makes it hard for outside forecasters to be able to predict exactly what the Office for National Statistics (ONS) will come up with).